Waterproofing material and process of making the same



Patented Apr. 9, 1929.

UNITED STATES 1,703,927 PATENT OFFICE.

LESTER KIRSGKBRAUN, OF CHICAGO, ILLINOIS.

WATERPROOFING MATERIAL AND PROCESS OF MAKING THE, SAME.

No Drawing.

This invention relates to improvements in waterproofing material and a process of making-the same and refers more particularly to a method of combining a bituminous a binder with pulp or fibrous material to fornr a waterproofing substance.

Among the salient objects of the invention are to provide a process incorporating comminuted particles of a bituminous binder to with a fibrous stock, the binder being incorporated into the body of the stock in a finely divided form and while in a relatively nonadhesive state; to provide a process in which a finely comminuted binder substance, such 115 as bituminous materials, asphalt or the like, in discrete form, is treated and mixed with a pulp or paper stock and the mixture run over a machine for forming it into sheets of various thicknesses; to provide ,a process in at which the relatively small particles of the binder are provided with an enveloping agent and are subsequently mixed with the fibrous stock from which sheets are formed on a paper or other sheet-forming machine and finallv the sheets subjected to heat whereby provide a process in which the enveloping agent carries and precipitates the binder upon the fibres attaching itmore fixedly thereto.

Heretofore, sheets have been made in which a comminuted asphaltic'or bituminous substance has been mixed with the pulp or fibrous stock and run over a sheet-forming machine a or molded. Such processes have been more or less successful where the binder used has been itch so hard as to possess the properties 0 an inert filler-rather than 'a binder with adhesive properties at normal temperatures. Among such pitches may be mentioned g lsonite, grahalnite, hard coal-tar pitch, rosin and even harder pitch of petroleum distilla tion which can be readily ground or reduced by mechanical means to a comminuted form. t5 Where, however, the pitches are of such char acter as to possess any appreciable adheslveness, such as is characteristic of the softer varieties of pitch, the introduction of such material into the paper stock has not resulted in a successful operation, owing to the tendency to gum the blankets, wires, driers and other essential parts of the machine.

While the softer and more adhesive bituminous binder may be rendered non-adhesive and most advantageously operable on a paper Application filed April 14, 1921, Serial No. 461,377. RenewedOetober 28, 1926.

machine by emulsification rather than by the herein disclosed process, nevertheless, blnders, which are somewhat adhesive at normal temperatures, may be successfully" introduced and handled on a paper machine by the present invention.

As distinguished from the binders usable in the present process the harder pitches are of such a refractory nature as to be incapable of spreading through the sheet, but remain in comminuted fo'rm in the finished product, requiring immersion in a hot waterproofing substance or solvent to melt the particles and produce a body sufficiently continuous to achieve a waterproof product.

It will be understood, of course, that even the refractory pitches will be more effecttively precipitated on to the fibres and carried into the sheet. i

The process disclosed in the present invention consists briefly, first, in mixing asphaltic, bituminous or other fusible waterproof binder materials ground or reduced to a finely divided condition or in comminuted v form in water with an agent which has the the fusible binder is caused to melt andag f glomerate about the fibrous stock, and to properties "of causing coagulation or precipitation of the binder particles on the fibres or forming uponthe particles of binder'enveloping coatings. Various agents may be used to produce this enveloping coating about the binder substance, preferably silicate of soda precipitated with aluminum sulphate, tri-sodiuni phosphate and zinc sulphate tanning liquors and sulphitc liquors precipitated with aluminum sulphate or analogous precipitates may be employed. The disclosure is not limited to the use of these agents, but includes such treatment as will produce, when observed microscopically, a nucleus of comminuted pitch surrounded by a protective medium or a distinct tendency of the binder particles to be precipitated upon the fibres. 'lhe'coating is produced by the action of the above-named agents added to the aqueous binder suspension in their proper order.

The present invention does not contemplate the emulsifioation of binder substances such as disclosed in United States Letters Patent 1,302,810, issued May 6th, 1919, in. which asphalt is very finely dispersed in emulsified form, but has to do with the enveloping of binder particles reducedmechanically to eomminuted form and subsequently treated in the manner described. The comminuted asphalt so treated may be mixed with a fibrous stock and run over a paper machine or other forming mechanisms and subsequently dried during which the envelopmg medium is broken so that the binder attaches itself to th'e fibres and incorporates therewith to produce a waterproof sheet.

I claim as my invention:

1. A process of making a waterproof-com-' stock and felting the stock-to form a sheet.

2. A process of making a waterproof composition-containing material, comprising reducing bituminous waterproofing material to relatively dry comminuted form, subsequent-lyenveloping the waterproofing material with a protective coating, mixing said material with fibrous stock and felting the stock to form a sheet.

3. A process of making a waterproof-composition-containing material, comprising reducing bituminous waterproofing material to comminuted form, enveloping the waterproofing material with a protective coating, precipating the waterproofing material on fibrous stock and, forming the stock into sheets.

4. A process of making waterproof composition, comprising reducing a waterproof binder to comminuted form, coating the hinder with a protective film, precipitating the binder on fibrous stock, forming the stock into sheets, and breaking the protective film.

5. A process of making waterproof composition, comprising reducing a waterproof binder to comminuted form, coating the binder with a protective film, precipitating the binder on fibrous stock, forming the stock into sheets, and breaking the protective film by the removal of water and the action of heat.

6. Waterproof composition comprising a felted fibrous sheet and a comminuted waterproof bituminous binder precipitated on the fibres.

7. A process of making a waterproof-composition-containing material, comprising reducing bituminous waterproofing material to commmuted form, and enveloping the waterproofing material with a protective substance.

-8. A process of making a waterproof-coniposition-containing material, comprising reducing normally adhesive bituminous waterproofing material to comminuted form, and enveloping the waterproofing material with a protective coating, thereby rendering the composition non-adhesive.

9. A waterproof-composition-containing material, comprising a base of comminuted bituminous substance, rendered non-adhesive by the addition thereto of an enveloping agent, said bituminous substance having the characteristics of having been comminuted by mechanical action.

10. A process of making a waterproof-composition-containing material comprising enveloping pitchy waterproofing material in finely divided comminuted condition with a protective coating, precipitating the waterproofing material on fibrous stock and forming the stock into sheets.

11. A composition capable of being sheeted comprising a fibrous stock and a comminuted waterproofing bituminous binder precipitated on the fibres.

12. A process of making a waterproof-composition-containing material comprising reducing a bitumen-pitch type waterproofing material to comminuted form by mechanical action, and enveloping the waterproofing niaterial with a protective substance.

13. A process of making a waterproof coniposition-containing material comprising comminuting a bitumen-pitch type waterproofing material and enveloping same with a protective coating.

14. A waterproof composition-containingmaterial comprising finely divided bitumenpitch type waterproofing material as a binder rendered non-adhesive by the addition thereto of an enveloping agent, said binder having the characteristics of having been finely divided byimechanical action, and fibre added to the mixture.

LESTER KIRSCHBRAUN. 

